This invention relates to devices for removing airborne contaminants created various types of surgery, in particular contaminants volatilized during laser surgery.
A number of different surgical techniques produce contaminants such as fumes, vapors and airborne particulates that are potentially harmful to surgeons medical staff. These contaminants may be produced during cautery, sawing, drilling and other procedures. Particularly severe problems occur during medical laser ablation, such as in excimer laser photoablation used in refractive eye surgery, removal of lesions, cosmetic surgery, etc.
Excimer laser photoablation has been a particularly rapidly growing technique in refractive eye surgery. This surgery results in a plume of smoke and particles at the surgery site. There is great concern about potentially debilitating and possibly lethal illnesses to surgeons and staff who are exposed routinely to the laser plume by inhalation of airborne byproducts that may include viruses, bacteria and pathogenic microbes. Also, chronic coughs, fatigue, nausea and other conditions affect many surgeons and staff members who undergo long-term exposure to this environment.
When an excimer laser is fired at the surface of an eye, typically at an ultraviolet wavelength of 193 nm the surface layer is volatilized through the breakdown of covalent bonds in organic material. An odor of burnt skin arises as particulates of various sizes and shapes are ejected into the environment. Often suction hoses are placed near the photoablation site to draw off a continuous stream of air entraining the particulates. However, these suction hoses are very loud, draw large volumes of air into the surgical field which potentially introduces pathogens into the field while not intercepting all of the particulates, including infectious viruses and bacteria.
A surgical laser smoke plume evacuator is described by Korenfeld in U.S. Pat. No. 5,941,873. This device uses an elongated tube having a central region bent into an approximately circular loop. The loop is placed in contact with an eye, surrounding the surgical field. A number of small holes penetrate the inner side of the loop. Air is drawn into the small holes by a vacuum system connected to the tube ends. Two of these loops may be stacked and used simultaneously. This arrangement will collect and remove a significant portion of the smoke plume resulting from laser impacts on the eye. However, because the loop is relative large in diameter, is not precisely circular and the collecting holes are relatively close to the eye surface, not all of the contaminants resulting from the laser impact may be collected. Particles that are ejected with some upward velocity may well escape the suction system.
Further, the evacuator of this Korenfeld patent may tend to slide over the surface of the eye during surgery, disturbing the surgeon performing the highly critical surgery and potentially damaging the eye. While including teeth along the lower edge are described in one embodiment, the teeth alone may be insufficient to prevent slipping, and could scratch the eye surface if moved.
Thus, there is a continuing need for improved devices and systems for assuring substantially complete capture and removal of all contaminants resulting from laser photoablation surgery and other surgical procedures that result in the release of particulates and vapors into the air around the surgical field and that will stay in place during surgery.
The above-noted problems, and others, are overcome in accordance with this invention by a vacuum chamber device including a tube having a surrounding wall, and inner and outer surfaces, a lower end for placing in contact with the surface of a laser surgery site such as an eye and an exposed, open upper end through which a laser beam enters to engage the surgical surface.
A first approximately annular channel is provided within the wall along the lower wall end, open to the lower end. A first air extraction tube penetrates the tube outer surface and communicates with the first chamber. When a vacuum is drawn on the first channel with the lower edge in contact with the surgical site, the resulting fixed vacuum in the first channel will securely hold the tube in place. Preferably, a portion of the tube lower edge is recessed to allow air to enter the tube along the eye surface.
A second annular channel is provided in the wall spaced from the upper and lower ends. A plurality of small holes extend through the inner wall surface in communication with the second channel. A second extraction tube penetrates the outer wall surface and communicates with the second channel. When a vacuum is drawn on the second extraction tube and second channel, air is extracted from within the tube, carrying with it an vapors, particulates, etc. formed by the laser operation.
A raised edge, preferably conforming to the tube shape, extends above a predetermined portion of the tube upper edge. A relatively large opening in the raised edge connects to a third extraction tube which when connected to a vacuum extraction system to draw a large volume of air across the top of the tube. This will assure that no vapors, particulates or the like can escape from the system and enter the surgical environment.
In certain surgical techniques, a tissue flap is formed, with a small tissue hinge connecting the flap to the adjacent tissue. A small ledge is preferably provided extending inwardly of the tube inner surface to protect such a hinge from exposure to the laser beam.